angle::Result VertexArray::getIndexRangeImpl(const Context *context,
DrawElementsType type,
GLsizei indexCount,
const void *indices,
IndexRange *indexRangeOut) const
{
Buffer *elementArrayBuffer = mState.mElementArrayBuffer.get();
if (!elementArrayBuffer)
{
*indexRangeOut = ComputeIndexRange(type, indices, indexCount,
context->getState().isPrimitiveRestartEnabled());
return angle::Result::Continue;
}
size_t offset = reinterpret_cast<uintptr_t>(indices);
ANGLE_TRY(elementArrayBuffer->getIndexRange(context, type, offset, indexCount,
context->getState().isPrimitiveRestartEnabled(),
indexRangeOut));
mIndexRangeCache.put(type, indexCount, offset, *indexRangeOut);
return angle::Result::Continue;
}
Error VertexArrayGL::syncIndexData(GLsizei count,
GLenum type,
const GLvoid *indices,
bool attributesNeedStreaming,
RangeUI *outIndexRange,
const GLvoid **outIndices) const
{
ASSERT(outIndices);
gl::Buffer *elementArrayBuffer = mData.getElementArrayBuffer().get();
// Need to check the range of indices if attributes need to be streamed
if (elementArrayBuffer != nullptr)
{
if (elementArrayBuffer != mAppliedElementArrayBuffer.get())
{
const BufferGL *bufferGL = GetImplAs<BufferGL>(elementArrayBuffer);
mStateManager->bindBuffer(GL_ELEMENT_ARRAY_BUFFER, bufferGL->getBufferID());
mAppliedElementArrayBuffer.set(elementArrayBuffer);
}
// Only compute the index range if the attributes also need to be streamed
if (attributesNeedStreaming)
{
ptrdiff_t elementArrayBufferOffset = reinterpret_cast<ptrdiff_t>(indices);
Error error = mData.getElementArrayBuffer()->getIndexRange(
type, static_cast<size_t>(elementArrayBufferOffset), count, outIndexRange);
if (error.isError())
{
return error;
}
}
// Indices serves as an offset into the index buffer in this case, use the same value for the draw call
*outIndices = indices;
}
else
{
// Need to stream the index buffer
// TODO: if GLES, nothing needs to be streamed
// Only compute the index range if the attributes also need to be streamed
if (attributesNeedStreaming)
{
*outIndexRange = ComputeIndexRange(type, indices, count);
}
// Allocate the streaming element array buffer
if (mStreamingElementArrayBuffer == 0)
{
mFunctions->genBuffers(1, &mStreamingElementArrayBuffer);
mStreamingElementArrayBufferSize = 0;
}
mStateManager->bindBuffer(GL_ELEMENT_ARRAY_BUFFER, mStreamingElementArrayBuffer);
mAppliedElementArrayBuffer.set(nullptr);
// Make sure the element array buffer is large enough
const Type &indexTypeInfo = GetTypeInfo(type);
size_t requiredStreamingBufferSize = indexTypeInfo.bytes * count;
if (requiredStreamingBufferSize > mStreamingElementArrayBufferSize)
{
// Copy the indices in while resizing the buffer
mFunctions->bufferData(GL_ELEMENT_ARRAY_BUFFER, requiredStreamingBufferSize, indices, GL_DYNAMIC_DRAW);
mStreamingElementArrayBufferSize = requiredStreamingBufferSize;
}
else
{
// Put the indices at the beginning of the buffer
mFunctions->bufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, requiredStreamingBufferSize, indices);
}
// Set the index offset for the draw call to zero since the supplied index pointer is to client data
*outIndices = nullptr;
}
return Error(GL_NO_ERROR);
}
